Non-sintered electrode with three-dimensional support for a secondary electrochemical cell having an alkaline electrolyte

Abstract

The invention provides an electrode comprising a porous three-dimensional conductive support containing an electrochemically active material, said support having at least a first edge connected to a connection piece and at least a second edge substantially parallel to said first edge, and means for preventing said active material disposed along said second edge from moving. Said means is selected from: a piece having a U-shaped fold placed stride said second edge; a surface covering; and treatment to modify the texture of said support. The electrode is used as a positive electrode in a second electrochemical cell of the nickel metal hydride type.

What is claimed is:  
     
       1. An electrode comprising a porous three-dimensional conductive support containing an electrochemically active material, said support having at least a first edge connected to a connection piece and at least a second edge substantially parallel to said first edge, and means for preventing said active material disposed along said second edge from moving, wherein said means is selected from the group consisting of: a piece having a U-shaped fold placed adjacent to and coextensive with said second edge; a covering deposited on a surface of said support and not penetrating said porous support; and treatment to modify the texture of said support. 
     
     
       2. An electrode according to  claim 1 , in which said piece is selected from the group consisting of a tape and a portion of a separator. 
     
     
       3. An electrode according to  claim 2 , in which said tape is constituted by an electrically insulating material. 
     
     
       4. An electrode according to  claim 3 , in which said material is selected from a polymer or a cellulose compound. 
     
     
       5. An electrode according to  claim 2 , in which said tape is made of metal. 
     
     
       6. An electrode according to  claim 1 , in which said piece is fixed to said electrode. 
     
     
       7. An electrode according to  claim 1 , in which said surface covering is deposited by spraying or by spreading. 
     
     
       8. An electrode according to  claim 7 , in which said covering is selected from the group consisting of: a polymer; an elastomer; a varnish; a paint; and a paraffin. 
     
     
       9. An electrode according to  claim 1 , in which said treatment is selected from the group consisting of: compression and welding. 
     
     
       10. An electrode according to  claim 9 , in which said treatment further comprises folding said second edge. 
     
     
       11. An electrode according to  claim 1 , in which said conductive support is selected from the group consisting of a foam and a felt. 
     
     
       12. An electrode according to  claim 11 , in which said conductive support is a nickel foam. 
     
     
       13. An electrode according to  claim 1 , in which said active material is a nickel hydroxide. 
     
     
       14. A secondary electrochemical cell including an electrode according to  claim 1 , in which said electrode is a nickel positive electrode. 
     
     
       15. A cell according to  claim 14 , wherein the cell is a nickel metal hydride cell.